Navigating a wire guide or catheter through a body passage can be especially problematic when attempting to negotiate a branching pathway, such as a bifurcated duct or vessel. Although adding steerability to a medical device is possible, it usually adds to the diameter of the device (a serious disadvantage in endoscopy) and may not result in a device having the desired characteristics. Most wire guides lack a satisfactory means to guide them in a particular direction, especially a direction that is against the natural pathway that the device wants to take. An example of an area of the body where this poses a problem is the biliary tree, where wire guides are often introduced prior to ERCP and other procedures involving the gall bladder, pancreas, liver, and associated ducts. The biliary tree includes bifurcations at the junction of the biliary and pancreatic ducts, as well as the right and left hepatic ducts. Using fluoroscopy or a cholangioscope, it is sometimes possible to successfully navigate the wire guide or device into the desired branch of the bifurcation; however, some anatomies can make that extremely difficult.
Adding steerability to a small-diameter wire guide like those used in endoscopy is generally not an option. One solution is to occlude the non-target branch of the bifurcation by inflating a balloon just past the junction. The balloon can be used to deflect a wire guide which is separately introduced through a different lumen of the scope, thereby directing it into the desired duct. While this method has been used successfully, a certain amount of trial and error is often required, primarily due to difficulties in visualizing the ducts and the lack of directional control over the wire guide. What is needed is a device that is configured such that the wire guide can be aligned with the occlusive means such that it reliably deflects it in a predictable manner and direction to successfully cannulate a particular branch of a bifurcated duct or vessel.